JP3108699B2 - Still video equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still video apparatus for recording an image signal on a recording medium such as a magnetic disk.

[0002]

2. Description of the Related Art Conventionally, a still video apparatus is configured to FM-modulate and record an input image signal.
The band of the signal recorded on the track of the magnetic disk is determined. Further, the width of this band is limited by the structural reason of the disk device and cannot be increased without limit.

For this reason, in a conventional still video device, even if a high quality image signal, that is, a wideband image signal is input to the still video device, the resolution of the image is limited. In particular, when this image is printed out, the image quality is limited. The decline is significant. Therefore, the present applicant has filed a patent application filed on July 16, 1991 with a configuration in which a wideband image signal is recorded by a narrowband still video device using means such as subsampling (decimation) or time axis conversion. Proposed. In this still video apparatus, an image signal corresponding to one screen is divided into a plurality of parts, expanded in the time axis, and recorded on another track of the magnetic disk.

[0004]

In such a configuration in which one screen is divided into a plurality of parts and recorded on a magnetic disk, an image signal corresponding to one horizontal scanning line is stored in, for example, two tracks of the magnetic disk. Have been. Therefore, if the levels of the amplitudes of the image signals in the respective tracks are different from each other, a seam corresponding to the divided portion appears on one reproduced screen, and a problem occurs that a good screen cannot be obtained. The present invention provides a configuration in which one screen is divided into a plurality of screens and recorded on a recording medium such as a magnetic disk.
It is an object of the present invention to provide a still video device in which a seam does not occur on a screen when an image signal is reproduced.

[0005]

A still video apparatus according to the present invention transmits an image signal corresponding to one screen to a screen.
And divided into a plurality by a line extending vertically, and means for recording each divided image signal to another track of the recording medium, when recording to the recording medium of the image signal, a predetermined amplitude level in the image signal and means for adding the reference signal,
Means for reproducing the image signal so that the reference signal has the same predetermined amplitude level as at the time of recording .

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 schematically shows an example of a recording mode of an image signal in a memory provided in the still video device of the present embodiment. In the figure, the number of scanning lines, the starting position of the scanning lines on the screen, and the like are not accurate. FIG. 1 shows a case where an image signal is recorded in a frame recording mode, and the number of scanning lines and the line frequency of an input image are the same as those in the still video format. (However, the band is twice as large as the band defined in the conventional still video.) That is, one screen is composed of a first field and a second field, and a scanning line indicated by a solid line in FIG. A1
A4 indicates the first field, and dashed scanning lines B1 to B4
4 indicates a second field. The screen is divided into two by a center line C extending in the vertical direction.

An image signal corresponding to the screen on the left side of the first field is stored in a first area of the memory. The image signal corresponding to the screen on the right side of the first field is stored in the third area of the memory. On the other hand, the image signal corresponding to the screen on the left of the second field is stored in the second area of the memory, and the image signal corresponding to the screen on the right of the second field is stored in the fourth area of the memory. The image signals stored in the first to fourth areas are recorded on the first to fourth tracks of the magnetic disk D, respectively.

FIG. 2 shows the relationship between an input image signal to the still video apparatus and an image signal stored on a magnetic disk as a recording medium. With reference to FIG. 1 and FIG. 1, the relationship between an input image signal, an image signal stored in a memory, and an image signal recorded on a magnetic disk will be described.

As described above, in the present embodiment, the image signal is recorded in the frame recording mode, so that the image signals of the first and second fields are input for one screen. An image signal forming one field includes a number of horizontal scanning lines H. An image signal corresponding to one horizontal scanning line H is composed of two horizontal synchronization signals S as shown in FIG.
Sandwiched between.

In the first field, the leftmost horizontal scanning line H in FIG. 2 comprises image signals A1 and A2, and the second horizontal scanning line H from the left comprises image signals A3 and A4. . The image signals A1 and A3 correspond to the left half of the screen, and are stored in the first area on the memory as shown in FIG. The image signals A2 and A4 correspond to the right half of the screen and are stored in the third area on the memory as shown in FIG. That is, when focusing on one horizontal scanning line H, a part corresponding to the left half of the screen is stored in the first area of the memory, and a part corresponding to the right half of the screen is stored in the third area of the memory.
Stored in the area. Similarly for the second field,
The image signals B1 and B3 corresponding to the left half of the screen are stored in the second area on the memory, and the image signals B2 and B4 corresponding to the right half of the screen are stored in the fourth area on the memory.

The image signals stored in the first to fourth areas of the memory are respectively recorded on the first to fourth tracks of the magnetic disk. Therefore, on the first track, the horizontal scanning line of the first field corresponding to the left half of the screen is recorded, and on the second track, the horizontal scanning line of the second field is recorded on the left half of the screen. The corresponding one is recorded. That is, when the first and second tracks are reproduced, an image in the left half of the screen is reproduced, and when the third and fourth tracks are reproduced, an image in the right half of the screen is reproduced. Also, the magnetic disk on which the image signal is recorded in such a correspondence relationship can be played back in a frame playback mode even in a conventional apparatus, whereby a high-definition video can be played back partly.

[0012] band of the image signal input to the still video unit is f _H, in the memory, the image signal is stored in the band f _H. When the image signal is read from the memory, the time axis is extended by a factor of two. That is, the band of the image signal recorded on the magnetic disk becomes f _{H /} 2. The band recorded on the magnetic disk is determined by the structure of the disk device, and it is not possible to record an image signal of a wider band. However, in this embodiment, the image signal can be divided with respect to the screen and stored in the memory, and the image signal can be read out of the memory by extending the time axis and stored in the magnetic disk in a predetermined band. Therefore, even if the band of the input image signal is wider than the band of the image signal recorded on the magnetic disk, the content of the input image signal can be stored as it is on the magnetic disk, and when a high-quality image signal is input. However, the image signal can be recorded on the magnetic disk while maintaining the image quality.

FIG. 3 is a block diagram of a recording system of a still video apparatus to which the first embodiment of the present invention is applied. The system control circuit 10 is a microcomputer and controls the whole still video device. The disk device has a magnetic head 11 and a spindle motor 12 for rotating and driving the magnetic disk D. Magnetic head 1
1 is controlled in tracking by the system control circuit 10 and is displaced along the radial direction of the magnetic disk D. The drive of the spindle motor 12 is controlled by the system control circuit 10, and rotates the magnetic disk D at a rotation speed of, for example, 3600 rpm. Magnetic disk D
While is rotating, the magnetic head 11 is positioned on a predetermined track of the magnetic disk D, and records an image signal and an ID code on this track. The recording amplifier 13 is controlled by the system control circuit 10 and outputs an image signal and the like to the magnetic head 11. The magnetic disk D is 52
Signals such as image signals are recorded on 50 tracks counted from the outermost track to the inner circumference side.

An operation unit 14 connected to the system control circuit 10 is provided for operating the present still video device. Note that an ID code relating to an image recorded on the magnetic disk D, that is, data such as a recording mode and a shooting date is also input via the operation unit 14.

A high-quality image signal obtained by a still video camera (not shown) or an external input terminal (not shown) includes a luminance signal (Y + S) and two color difference signals (RY, BY). Is input to the still video device. In the drawing, the symbol (H) given to the luminance signal and the color difference signal means high image quality. Luminance signal (Y + S)
Are separated from the luminance signal (Y + S) by the synchronization signal separation circuit 21 and sent to the memory control circuit 22 and the system control circuit 10. The memory control circuit 22 controls the AD converters 23, 24, 25, the Y memory 26, the RY memory 27, and the BY memory 28 based on the horizontal synchronization signal S. Also, the memory control circuit 22 outputs a DA signal based on a synchronization signal from a synchronization signal generation circuit 34 described later.
It controls converters 31, 32, 33, Y memory 26, RY memory 27 and BY memory 28.

A luminance signal (Y + S) including a horizontal synchronizing signal
The luminance signal Y recorded between the two horizontal synchronizing signals is stored in the Y memory 26 under the control of the memory control circuit 22.
Similarly, the color difference signal (RY) is AD-converted by the AD converter 24 and stored in the RY memory 27. The color difference signal (BY) is AD-converted by the AD converter 25 and stored in the BY memory 28.

Y memory 26, RY memory 27 and B memory
The luminance signal Y and the color difference signal (R
−Y, BY) are DA-converted by the DA converters 31, 32, 33, respectively, based on the synchronization signal (reference clock signal) output from the synchronization signal generation circuit 34.
At this time, the reference clock signals are stored in the memories 26, 27, and 28.
For example, it has a half frequency as compared with a reference clock signal used for recording an image signal. Therefore, the image signal is read out from each of the memories 26, 27, 28 at a relatively low speed, whereby the time axis is expanded. As will be described later, the DA-converted luminance signal Y is input to a Y recording processing circuit 35 with a reference signal added thereto, and is subjected to processing such as FM modulation. Similarly, the two color difference signals (RY, BY) that have been DA-converted are input to the C recording processing circuit 36 with the reference signal added thereto, and
Processing such as modulation is performed.

The reference signal generation circuit 81 outputs a square wave signal (ie, a reference signal) having a predetermined amplitude based on the pulse signal output from the synchronization signal generation circuit 34. Gate circuit 82 outputs a gate pulse for passing the reference signal output from reference signal generation circuit 81. That is, while the gate pulse is output, the reference signal output from the reference signal generation circuit 81 is added to the adder 8
3 and is added to the luminance signal Y output from the DA converter 31. The relationship between the luminance signal Y and the reference signal, and the relationship between the color difference signals (RY, BY) and the reference signal described below will be described later in detail.

The reference signal output from the reference signal generating circuit 81 is added to adders 85 and 86 through a gate circuit 84.
And added to the color difference signals (RY, BY) output from the DA converters 32 and 33, respectively.

The ID code input via the operation unit 14 and the system control circuit 10 is subjected to processing such as DPSK modulation in the ID recording processing circuit 37.

The DPSK-modulated ID code, the FM-modulated luminance signal and the chrominance signal are superposed by an adder 38, amplified by a recording amplifier 13, and sent to a magnetic head 11. Then, the ID code, the luminance signal and the color difference signal are recorded on predetermined tracks of the magnetic disk D by the magnetic head 11. As described above, the signal recorded on the magnetic disk D is expanded in time as compared with the signal input to the present still video device. As described above with reference to FIGS. 1 and 2, the input image is divided and divided into the memories 26 and 2 in order to record the image signal on the magnetic disk D after the time axis expansion.
7, 28.

FIG. 4 shows the relationship between the image signal (that is, the luminance signal Y) input to the Y recording processing circuit 35 and the reference signal R. The luminance signal Y corresponds to one horizontal scanning line, and a horizontal synchronization signal S is provided before each luminance signal Y. Further, a reference signal R is provided between the luminance signal Y and a horizontal synchronization signal S 'located before the luminance signal Y' following the luminance signal Y. Horizontal synchronization signals S, S '
Is a negative signal and has the opposite polarity to the luminance signal Y, but the reference signal R is a positive square wave signal and has the same polarity as the luminance signal Y. The amplitude of the reference signal R is, for example, 40 IRE. The luminance signal Y stored in the Y memory 26 is adjusted so that “white” having the highest brightness becomes 100 IRE. Therefore, in the signal stored in the Y recording processing circuit 35, the reference signal R is “white”. 40% of
. Note that the color difference signals (RY, B-
Similarly for Y), a reference signal having an amplitude of, for example, 40 IRE is provided between the subsequent horizontal synchronizing signal.

In the reproduction system of the present still video apparatus, as will be described later, the amplitude of the image signal is adjusted based on the reference signal added to the image signal, and the reproduction of the image signal is performed.

Next, the configuration of the reproduction system of the still video device will be described with reference to FIG. System control circuit 1
The magnetic head 11, the magnetic head 11, the spindle motor 12, and the operation unit 14 are also included in the recording system shown in FIG. 1, that is, they serve both as a recording system and a reproducing system.

The magnetic head 11 is located on a predetermined track of the magnetic disk D, and reproduces an ID code and an image signal recorded on this track. The reproduction amplifier 41 reads out the image signal and the ID code recorded on the magnetic disk D, and performs a Y reproduction processing circuit 42, a C reproduction processing circuit 43,
Output to the D reproduction processing circuit 44. The Y reproduction processing circuit 42 FM-demodulates the luminance signal (Y + S) including the horizontal synchronization signal and outputs the result. The C reproduction processing circuit 43 outputs the color difference signal (R-
Y, BY) are FM-demodulated and output. The ID reproduction processing circuit 44 demodulates the ID code by DPSK and outputs the result.

The amplitude of the output signal of the Y reproduction processing circuit 42 (that is, the luminance signal (Y + S)) is adjusted to a predetermined level by an automatic gain control (AGC) circuit 91. The synchronization signal separation circuit 45 extracts the horizontal synchronization signal S from the luminance signal (Y + S) output from the AGC circuit 91. The reference signal extraction circuit 92 outputs the luminance signal (Y +
The reference signal R is derived from S). The horizontal synchronization signal S is sent to the memory control circuit 46 and the system control circuit 10, and the reference signal R is sent to the error detection circuit 93. The error detection circuit 93 determines that the amplitude of the reference signal R is 40I
The AGC circuit 91 is controlled so as to become RE. This A
The output signal (luminance signal (Y + S)) of the GC circuit 91 is again input to the synchronization signal separation circuit 45 and the reference signal extraction circuit 92, and the horizontal synchronization signal S and the reference signal R are extracted as described above. By such feedback control, the output signal of the AGC circuit 91 is adjusted such that the amplitude of the reference signal R included therein becomes 40 IRE.

Similarly, the color difference signals (RY, BY) are controlled by the AGC circuit 94, the reference signal extracting circuit 95, and the error signal detecting circuit 96. That is, A
The output signal of the GC circuit 94 (that is, the color difference signal (RY,
BY)) are adjusted such that the amplitudes of the reference signals R included therein become 40 IRE, respectively.

The memory control circuit 46 controls the A / D converter 47 and the Y memory 51 based on the horizontal synchronizing signal S, and the A / D converter 48 and the C memory 52
Control. In addition, the memory control circuit 46, based on a synchronization signal from a synchronization signal generation circuit 53 described later,
The DA converters 54, 55, 56, the Y memory 51, and the C memory 52 are controlled.

Luminance signal (Y + S) including horizontal synchronizing signal
The luminance signal Y recorded between the two horizontal synchronizing signals is stored in the Y memory 51 under the control of the memory control circuit 46.
The luminance signal Y stored in the Y memory 51 is a synchronization signal (reference clock signal) output from the synchronization signal generation circuit 53.
Is DA-converted by the DA converter 54 based on
Similarly, the color difference signals (RY, BY) are converted by the AD converter 48.
And is stored in the C memory 52. The color difference signals (RY, BY) are alternately output from the C memory 52 based on the reference clock signal, but the color difference signals (RY, BY) of the same horizontal scanning line are output from the memory control. Due to the operation of the circuit 46, the signals are simultaneously output from the synchronizing circuit 57 and input to the D / A converters 55 and 56, respectively.
A conversion is performed.

The reference clock signal has, for example, twice the frequency of the reference clock signal used to record the image signals in the memories 51 and 52. Therefore, the image signal is read out from each of the memories 51 and 52 at a relatively high speed, whereby the time axis is compressed.

Blanking sync mix circuits 61 and 6
Reference numerals 2 and 63 are provided to set a predetermined portion in front of each luminance signal (Y + S) and two color difference signals (RY, BY) to a signal of 0 level and to superimpose a synchronization signal. The blanking sync mix circuits 61 and 6
According to 2, 63, a clean synchronization signal conforming to each system such as HDTV (high definition television) is added before these signals. And blanking sync mix circuit 6
Signals (Y + S), (RY),
(BY) is a television signal conforming to, for example, the HDTV system (for example, a high-definition television system), and is directly input to a display device (not shown).

On the other hand, I stored in the magnetic disk D
The D code is subjected to processing such as DPSK demodulation in the ID reproduction processing circuit 44 and is decoded by the system control circuit 10.

As described above, in this embodiment, when recording an image signal on a magnetic disk, the reference signal R having an amplitude of 40 IRE is added to the image signal adjusted so that "white" becomes 100 IRE. doing. Therefore,
When reproducing the image signal, as described above, this reference signal R
By adjusting the amplitude of the image signal so that the amplitude of the image signal becomes 40 IRE, the image signal has the same amplitude as when recording on the magnetic disk D. That is, the image signal corresponding to each divided screen is controlled so as to have the same amplitude (brightness) as before the division, and therefore, even if one screen is divided into two as shown in FIG. There is no seam on the reproduced screen.

FIG. 6 is a block diagram of a recording system of a still video apparatus to which the second embodiment of the present invention is applied. here,
Only parts different from the configuration of the first embodiment shown in FIG. 3 will be described.

The phase locked loop (PLL) circuit 71 outputs a sine wave signal having a fixed phase difference and a fixed frequency ratio with respect to the sampling clock signal output from the memory control circuit 22. . Gate circuit 72 allows the sine wave signal output from PLL circuit 71 to pass while the gate signal is output from synchronization signal generation circuit 34. Such a sine wave signal (reference burst signal) output from the PLL circuit 71 while the gate pulse is output is used as a reference signal by the adder 7.
3 and is added to the luminance signal Y output from the DA converter 31. This reference burst signal is a reference signal used for adjusting the amplitude of the image signal, as in the first embodiment, and both amplitudes are, for example, 40 IRE.
The reference burst signal is also used to correct the influence of the jitter of the disk device as described later. The relationship between the luminance signal Y and the reference burst signal, and the relationship between the color difference signals (RY, BY) and the reference burst signal described below will be described later in detail.

Similarly, the PLL circuit 74 outputs a clock signal having a fixed phase difference and a fixed frequency ratio with respect to the sampling clock signal output from the memory control circuit 22. The sine wave signal is output while is output. The sine wave signal (reference burst signal) output by the gate pulse is input to adders 76 and 77,
33 are added to the color difference signals (RY, BY) output from the pixel 33.

FIG. 7 shows the image signal (that is, the luminance signal Y) input to the Y recording processing circuit 35 and the reference burst signal T.
The relationship is shown below. The luminance signal Y corresponds to one horizontal scanning line, and a horizontal synchronization signal S is provided before each luminance signal Y. Further, a reference burst signal T is provided between the luminance signal Y and a horizontal synchronization signal S ′ located before the luminance signal following the luminance signal Y. The reference burst signal T is a signal that oscillates above and below the 0 level. The reference burst signal T oscillates at a predetermined frequency. Similarly, a reference burst signal is provided between the color difference signals (RY, BY) and a subsequent horizontal synchronization signal.

Next, the addition of the reference burst signal to the image signal will be described with reference to FIG. The sampling clock signal P is output from the memory control circuit 22. In addition to the generation of the reference burst signal described below,
It is also used to control the operation of the DA converter 31 and the like. Between an image signal (a luminance signal Y is shown as an example in FIG. 8) and a horizontal synchronizing signal S ′ following this,
A period in which there is substantially no image signal is provided. This is obtained by stopping the reading of the image signal from the memory early. The reference burst signal T is the luminance signal Y
And the following horizontal synchronization signal S '. FIG. 8 shows that when the frequency of the reference burst signal is の of the sampling frequency,
3 are respectively shown.

The sampling clock signal P is input to the PLL circuit 71. The PLL circuit 71 has a certain phase difference with respect to the sampling clock signal, and has a frequency (sampling frequency) of the sampling clock signal.
A sine wave signal having a frequency smaller than the frequency by a predetermined ratio is output. That is, the frequency of the sine wave signal is, for example, 1/2, 2/3 of the sampling frequency. In addition,
When this ratio is 1 / integer, the PLL circuit 71 (and
74) can be replaced by a frequency divider (counter),
The circuit configuration is simplified. The synchronization signal generation circuit 34 outputs a reference burst signal insertion gate pulse U to the gate circuit 72. This gate pulse U is output between the luminance signal Y and the subsequent horizontal synchronization signal S ′. During the output period of the gate pulse U, the sine wave signal is output to the adder 73 and added as a reference burst signal T between the luminance signal Y and the subsequent horizontal synchronization signal S ′.

In the reproduction system of the present still video apparatus, as will be described later, the reference burst signal added to the image signal functions as a reference signal as in the first embodiment, and a sampling clock is generated based on the reference burst signal. Is generated, and the image signal is reproduced according to the sampling clock.

Next, the configuration of the reproduction system of the still video device will be described with reference to FIG. Here, only portions different from the configuration of the first embodiment shown in FIG. 5 will be described.

The burst extraction circuit 101 has an AGC circuit 9
A reference signal, that is, a reference burst signal T, is extracted from the luminance signal (Y + S) output from 1. This reference burst signal T is sent to the envelope detection circuit 102. The envelope detection circuit 102 performs envelope detection of the reference burst signal T, and outputs an envelope signal of the signal T to the error detection circuit 93. The error detection circuit 93 detects that both amplitudes of the envelope signal of the reference burst signal T are 40 IRE.
The AGC circuit 91 is controlled so that This AGC
The output signal (luminance signal (Y + S)) of the circuit 91 is input again to the synchronization signal separation circuit 45 and the burst extraction circuit 101, and the horizontal synchronization signal S and the reference burst signal T are extracted as described above. By such feedback control, the output signal of the AGC circuit 91 is adjusted such that the amplitude of the reference signal R included therein becomes 40 IRE.

Similarly, the color difference signals (RY, BY) are controlled by the AGC circuit 94, the burst extraction circuit 103, the envelope detection circuit 104, and the error signal detection circuit 96. That is, the output signals of the AGC circuit 94 (that is, the color difference signals (RY, BY)) are adjusted such that both amplitudes of the envelope signal of the reference burst signal T included therein become 40 IRE.

In the reference burst signal T, “white” is 100I
For an image signal adjusted to be RE, 40I
It has both amplitudes of RE. Therefore,
When reproducing the image signal, as described above, the image signal is adjusted by adjusting the amplitude of the image signal so that both amplitudes of the reference burst signal T become 40 IRE.
Will have the same amplitude as when recording to That is,
The image signal corresponding to each of the divided screens is controlled so as to have the same amplitude (brightness) as before the division, and even if one screen is divided into, for example, two as in the first embodiment,
There are no seams on the reproduced screen.

The PLL circuit 105 generates a pulse signal having the same high frequency as the sampling clock signal P (FIG. 8), divides the frequency of the high frequency pulse signal, and sets the frequency of the reference burst signal set in the recording system. A pulse signal having a frequency corresponding to a ratio (for example, 1/2, 2/3) between the pulse signal and the sampling frequency is generated. That is, the PLL circuit 105 generates a pulse signal having the same frequency as the reference burst signal T. Next, the PLL circuit 105 compares the phase difference between the pulse signal and the reference burst signal T output from the burst extraction circuit 101, and the phase difference is compared with the sampling clock signal P set in the recording system and the reference burst signal T. Finely adjust the phase of the pulse signal so as to match the phase difference. This fine adjustment of the phase is performed a plurality of times in accordance with the frequency of the reference burst signal (if the reference burst signal vibrates five times, for example, the fine adjustment can be performed five times). During the adjustment, the phase of the pulse signal will be adjusted accurately. And PL
The L circuit 105 continues to output the sampling clock signal P having the same phase as the pulse signal. Thus, the same sampling clock signal P as that of the recording system
It is output by the L circuit 105.

Similarly, the sampling clock signal P is generated by the burst extraction circuit 103 and the PLL circuit 106 for the color difference signals (RY, BY).

The reference burst signal T is provided integrally with the image signal. When the image signal fluctuates back and forth due to the jitter of the disk device, the reference burst signal T also fluctuates in synchronization with this. Therefore, by using the reference burst signal T, it is possible to generate a sampling clock signal that is not affected by jitter.

As described above, in the second embodiment, at the time of recording the image signal on the magnetic disk, the reference burst signal having a predetermined amplitude between the image signal and the horizontal synchronizing signal (ie, the reference burst signal) based on the sampling clock signal. Signal is inserted, and when the image signal is reproduced, the amplitude of the image signal is adjusted based on the reference burst signal. Therefore, as in the first embodiment, it is possible to obtain an image in which no seams appear on the screen. In this embodiment, a sampling clock is generated during reproduction based on the reference burst signal. Since the reference burst signal fluctuates integrally with the image signal, the positional relationship with the image signal remains unchanged even when jitter occurs in the disk device. Further, since the reference burst signal is a signal oscillating at a predetermined frequency, the PLL circuits 105 and 106 perform
The phase difference between the pulse signal and the reference burst signal can be compared a plurality of times, during which the phase of the pulse signal can be adjusted with high precision, and the same sampling clock signal as during recording can be generated. Therefore, even if jitter occurs in the disk device, sufficient jitter correction can be performed, and a high-quality screen can be reproduced.

[0049]

As described above, according to the present invention, when one screen is divided into a plurality of parts and recorded on a recording medium, the recorded image is reproduced without generating a seam on the screen when reproducing the image signal. That the reproduced image can be faithfully reproduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a recording mode of an image signal stored in a memory of a still video device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a relationship between an image signal input to a still video device and an image signal stored on a magnetic disk.

FIG. 3 is a block diagram showing a recording system of the still video device to which the first embodiment of the present invention is applied.

FIG. 4 is a diagram showing an image signal, a horizontal synchronization signal, and a square wave signal (reference signal).

FIG. 5 is a block diagram showing a reproduction system of a still video device to which the first embodiment of the present invention has been applied.

FIG. 6 is a block diagram illustrating a recording system of a still video device to which the second embodiment of the present invention has been applied.

FIG. 7 is a diagram illustrating an image signal, a horizontal synchronization signal, and a reference burst signal (reference signal).

FIG. 8 is a diagram showing a sampling clock signal, an image signal, a reference burst signal (reference signal), and a gate pulse.

FIG. 9 is a block diagram showing a playback system of a still video device to which the second embodiment of the present invention has been applied.

[Explanation of symbols]

 D Magnetic disk (recording medium) R Reference signal T Reference burst signal (reference signal) Y Image signal

Claims (3)

(57) [Claims] 1. An image signal corresponding to one screen is converted to the image signal .
Means for dividing the image signal into a plurality of lines by a line extending in the vertical direction with respect to the surface, and recording the divided image signals on different tracks of the recording medium, and when the image signal is recorded on the recording medium, a predetermined amplitude and means for adding the level of the reference signal, still video apparatus characterized by comprising a means for reproducing the image signal as the reference signal is the same predetermined amplitude level during recording. 2. The still video apparatus according to claim 1, wherein said reference signal is a square wave signal. 3. The still video apparatus according to claim 1, wherein said reference signal is a burst signal having a predetermined frequency.